1. Field of the Invention
This invention concerns suspensions permitting limited turning of a rotor that is held under tension and subjected to a controlling torque.
The primary object of the invention is to provide very inexpensive suspension for a permanent magnet rotor that is coupled to a source of tension, such as a longitudinally tensioned louver in an array of magnetically controlled louvers.
2. Description of the Prior Art
The applicant's U.S. Pat. No. 3,742,648 discloses a link suspension for an array of powered louvers in which pivot pins are received in concave dimples to afford low frictional torque and obviate unwanted restoring torques which increase with the angle of rotation. The prior art is rich in such pivot designs and their derivatives in which a convex bearing surface is received in a concave bearing surface. The use of two engaging and opposing concave surfaces in such bearings is not found.
Common experience with chains teaches that despite the facility of adjacent links to assume large angles relative to each other in orthogonal planes, links that are under tension repose with the planes that contain their narrow dimensions mutually perpendicular and resist twisting with a mechanical restoring torque that increases rapidly as the angle of torsion between the links increases.